Rammed earth offers an economical and sustainable alternative to concrete. The problem like shrinkage, proper soil selection, low compressive strength, cracking, durability aspects is rammed earth construction. One way to address these problems is to stabilize rammed earth. The primary objective of this study is to make use of the RHA(waste material) with NS and understand its effects on the geotechnical properties, compressive strength & weathering. The proctor tests results indicates that with the increase in RHA percentage there was an increase in the Optimum Moisture Content (OMC) and reduction in the Maximum Dry Density (MDD). The cube compressive strength values decreased with subsequent addition of RHA to its maximum at 5% RHA. The deterioration is increases with increasing in RHA content

1. International Journal for Scientific Research & Development (IJSRD) | Vol. 1, Issue 1, 2013 | ISSN(online): 2321-0613
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Rice husk ash as a stabilizer in rammed earth
Vismay Shah
1
Sandeep Khorasiya
2
Ankit Patel
3
Abhijitsinh Parmar
4
1,2
M.E. Scholar, Civil Engineering Department
3,4
Assistant Professor, Civil Engineering Department
1,2
Government Engineering College, Modasa
3,4
Shankarsinh Vaghela Bapu Institute of Technology, Gandhinagar
Abstract-Rammed earth offers an economical and
sustainable alternative to concrete. The problem like
shrinkage, proper soil selection, low compressive strength,
cracking, durability aspects is rammed earth construction.
One way to address these problems is to stabilize rammed
earth. The primary objective of this study is to make use of
the RHA(waste material) with NS and understand its effects
on the geotechnical properties, compressive strength &
weathering. The proctor tests results indicates that with the
increase in RHA percentage there was an increase in the
Optimum Moisture Content (OMC) and reduction in the
Maximum Dry Density (MDD). The cube compressive
strength values decreased with subsequent addition of RHA
to its maximum at 5% RHA. The deterioration is increases
with increasing in RHA content
I. INTRODUCTION
Rammed earth is known as a material as well as
construction technique where soil is taken from the ground
and compacted to form structures. The soil compacted in
removable formwork. Rammed earth buildings are found
around the Mediterranean, and along the same latitude in
Iran, Pakistan, India and China.
The Great Wall of China is also constructed with
rammed earth. Rammed earth was taken by the Europeans to
South America, and many colonial buildings in parts of
Brazil and Columbia are constructed in rammed earth. The
rediscovery of rammed earth as a sustainable building
material prompted its use in Australia and the southern
United States from the early 1970s onward.
Today rammed earth is receiving increased interest
as sustainable construction practices become more main
stream. Rammed earth constructions can be classified into
two broad categories: stabilized rammed earth and un-
stabilized rammed earth. Unsterilized rammed earth is made
from mainly soil, sand and gravel. Whereas stabilized
rammed earth contains additives like cement or lime in
addition to soil, sand and gravel.
In country like India traffic on National or State
Highway is near to 4500 CVD, hence m.s.a is near to 150
m.s.a. If those Highways are constructed in Black cotton soil
it becomes problematic due to its characteristics.
II. OBJECTIVES
This research will draw a comparison between the NS
available locally in Ahmadabad &available literatures
thereby indicating the suitability of NS for the use of RE.
Since there are very few guidelines available for rammed
earth when combined with a waste material like RHA.
The primary objective of this study is to make use
of the RHA (waste material) with NS and understand its
effects on the geotechnical properties, compressive strength
& weathering.
The study also intends to quantify the amount of
RHA to be added to the NS according to the values of soil
properties measured, in order to enhance the properties of
rammed earth. Establishing properties of locally available
natural soil and comparing it with properties of soil suitable
for rammed earth construction as per published literature.
III. EXPERIMENTAL PROGRAM
1) Collection of soil sample
2) Establishing soil properties
3) Proportioning with RHA & re-establishing its properties
4) Ns + RHA (5, 10, 15%)
5) Further investigation by analyzing its UCS, cube
compressive strength results at various moisture contents
and weathering results
Following tests are carried out.
Geotechnical Properties
 Grain Size Distribution,
 Plastic Index,
 Shrinkage,
 Swelling,
 Dry Density and Moisture Content etc
Compressive Strength
 Unconfined Compressive Strength
 Cube Compressive Strength,.
Weathering Effect
 Spray Test.
IV. RESULTS
Fig 1: MDD (g/cc) versus RHA (%)
1.60
1.70
1.80
1.90
5 10 15
MDD
RHA
NS+RHA
NS+RHA

2. Rice husk ash as a stabilizer in rammed earth
(IJSRD/Vol. 1/Issue 1/2013/0005)
All rights reserved by www.ijsrd.com 16
Fig. 2. OMC (g/cc) versus RHA (%)
The proctor tests results shown in the Figure 1 and 2
indicated that with the increase in RHA percentage there
was an increase in the Optimum Moisture Content (OMC).
It was also observed that with the increase in RHA
percentage there was a reduction in the Maximum Dry
Density (MDD)
Fig. 3. Unconfined compressive strength of NS with various
percentage of RHA
The UCS values decreased with subsequent addition of
RHA to its maximum at 5% RHA. As shown in Figure 3.
Decreasing in UCS value may be due to the excess RHA
introduced to the soil and therefore forming weak bonds
between the soils.
Fig. 4 Cube compressive strength of NS with various
percentage of RHA
The cube compressive strength values decreased with
subsequent addition of RHA to its maximum at 5% RHA as
shown in Figure 4
 Weathering test:
Proportion
Time
taken(mi
n) for
test
Deteriorati
on (%)
Type
Ns 45 95 Disintegration
5% rha+95% ns 40 95 Disintegration
10% rha+90% ns 35 95 Disintegration
15% rha+85% ns 21 95 Disintegration
Table 1 – Results for Spray Test
As shown in table 1 as percentage of RHA increase the
deterioration time decreases. At the 15 % RHA content the
deterioration takes place about 95 % in only 21 minutes.
V. CONCLUSION
There was a decrease in the MDD on addition of RHA.
There was an increase in the Optimum Moisture Content
(OMC) from 9.84% to 19 % on addition of RHA. The
decrease in the MDD can be attributed to the replacement of
soil and by the RHA in the mixture which have relatively
lower specific gravity compared to that of the soil. Also
since RHA has a low specific gravity & is inherently a
weaker material than NS, there is reduction in the UCS
values. From table 1. it was observed that when spray test
was conducted on 100% N.S. sample the soil sample
disintegrated in 45 min whereas when weathering test was
conducted on N.S. + varying % of RHA
(5%,10%,15%)cubes, the sample had disintegrated in 20 to
30 min. There is a reduction in compressive strength when
RHA is added to NS due to the lack of formation of
cementation compounds so addition of cement or lime is
must require for stabilization of rammed earth.
REFERENCES
[1] Prasanna Kumar P, “Stabilised Rammed Earth for Walls:
Materials, Compressive Strength and Elastic Properties”,
Department of Civil Engineering. IISc, Bangalore, July
2009
[2] Peter Walker, Rowland Keable, Joe Martin, and Vasilios
Maniatidis., “Rammed earth design and construction
guidelines”, BRE Bookshop Publications, UK, 2005
[3] I.S: 1905 - 1987(reaffirmed 1988), “Code of Practice for
Structural Use of Unreinforced Masonry”, Bureau of Indian
Standards, New Delhi, India.
[4] SP: 36 (Part I) – 1987,
[5] SP: 36 (Part II) – 1988 (reaffirmed 1995), “Field [6] [6]
Testing of Soils for Civil Engineering Purposes”,
[7] IS 1498-1970, ”Classification and Identification of soil
for general engineering purpose”.
[8] IS 1725-1982, ”Specification for soil based blocks used
in general building construction”.
0
10
20
0 10 20
OMC(%)
RICE HUSK ASH CONTENT(%)
NS+RHA
NS+RHA
0.000
0.500
1.000
1.500
2.000
2.500
3.000
3.500
100% NS 85%soil+15%RHA
UCS(N/mm^2)
UCS at OMC
UCS after
drying
0.000
0.200
0.400
0.600
0.800
1.000
1.200
95%soil+5%RHA 85%soil+15%RHA
CUBEstrength(N/mm^2)
Cube
strength
at OMC
(N/mm^2)
cube
strength
after
drying
(N/mm^2)

3. Rice husk ash as a stabilizer in rammed earth
(IJSRD/Vol. 1/Issue 1/2013/0005)
All rights reserved by www.ijsrd.com 17
[9] IS 2720 (Part 10)-1991, “Method of Test for Soil
(Determination of UCS)”.
[10] IS 2720 (Part 20)-1992, “Method of Test for Soil
(Determination of Linear Shrinkage)”.
[11] IS 2720 (Part 4)-1985, “Method of Test for Soil (Grain
Size Analysis)”.
[12] IS 2720 (Part 40)-1977, “Method of Test for Soil
(Determination of Free Swell Index)”.
[13] IS 2720 (Part 5)-1985, “Method of Test for Soil
(Determination of LL and PL)”.